Air-feed control for rock drills



L.. c. BAYLES. AIR FEED CONTROL FOR Roux DRILLS Filed may 2'3 1921 yJeaINVENTOR Zmwia @fia Hi5 ATTVO EY Patented Apr. 17, 1923.

LEWIS C. BAYLES, 0F EASTON, PENNSYLVANIA, ASSIGNOR INGERSOLL-RANL)COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

AIR-FEED CONTROL FOR ROCK DEILLS.

Application filed May 23,

T 0 (all whom it may concern Be it known that I, LEWIS C. BAYLEs, acitizen of the United States, and a residentof Easton, NorthamptonCounty, State of Pennsylvania, have invented a certain Air- Feed Controlfor Rock Drills of which the following is a specification accompanied bydrawings.

This invention relates to fluid pressure rock drills of the hammer typehaving automatic rotation for the drill steel dependent upon the hammerpiston, as for instance rifle bar rotation, as distinguished fromindependent rotation, but relates more particularly to automatic'controlfor the feeding element which advances the machine.

This feeding element may be an air feed cylinder and piston or otherfluid actuated device, and the objects of the invention are to enablethe air feeding element to be automatically controlled by the rotationdevices in accordance with or responsively to the resistance torotation.

Various means may be devised for so controlling the feeding means in arock drill of the type referred to without departing from the spirit ofmy invention as shown and described herein and defined in the appendedclaims, and I have illustrated one preferred form of the invention inthe accompanying drawings in which- Figure 1 is a vertical sectionalelevation of a stope drill constructed in accordance with my invention;

Figure 2 is a horizontal sectional view on the line 22 of Figure 1 withthe air feed controlling valve closed;

Figure 3 is a view similar to Figure with the said valve open, and

Figure 4c is a transverse sectional view on the line 4-4 of Figure 1.

Referring to the drawings, only so much of the operative parts of a rockdrill are shown as will serve to illustrate the invention, and thoseportions which can be shown diagrammatically for clearness are soindicated, as for instance the drill casing and the ports and passagestherein.

The cylinder A is provided with the front head B containing the rotationsleeve G into which the drill steel D extends in the usual manner. Areciprocating hammer piston E of the valveless type is illustratedformed with a head F and a forwardly extending 1921. Serial No. 471,903.

reduced and fluted shank G extending through the front cylinder bushingG and having slidable but non-rotative engagement with the rotationsleeve C. A rearwardly extending piston shank H is formed with a reducedneck J and the cylinder is formed with the supplyv passages K and L andthe exhaust port C) controlled by the hammer piston in the usual manneras well understood.

The cylinder is provided with the back cylinder portion P containing aratchet ring Q loosely held between a plate R and the head block S. Arifle bar T engages the piston shank H and is provided with a head Uwithin the ratchet ring Q and the usual spring pressed pawls V areadapted to cngage the teeth of the ratchet ring Q and hold the rifle barstationary as the piston moves in one direction thereby impartingrotation to the drill steel.

The throttle valve W mounted in the head block S and provided with thehandle X controls the supply of motive fluid from the supply pipe Y tothe percussive element and also to the feeding element which is shown inthis instance in the form of a cylinder Z on which the percussiveelement is mounted in any suitable manner as by means of the collar othe parts forming the casing of the percussive element and the feedingelement being adapted to be held together by the usual side bolts 7)indicated in sectional view in Figures 2 and 3. The feed cylinder Z isprovided with a piston 0 having a piston rod d in slidable butnonrotative engagement therewith. For this purpose the piston rod may beformed with the grooves 6 adapted to engage projections f at therearward or lower end of the feed cylinder Z. A claw foot 9 of anysuitable construction may be transversely pivoted at h to the end of thepiston rod cl.

In accordance with this invention. the actuating devices dependent uponthe hammer piston for rotating the drill steel also actuate a valve orother suitable device for controlling the air feed means automaticallyand responsively to the resistance to rotation. This may be accomplishedby automatically opening an'exhaust passage 7a in the head block S fromthe feed cylinder to the atmosphere at the exhaust port 7' in the backcylinder portion P although it is understood that this exhaust passageand exhaust port may be arranged in any suitable location. An air feedcontrolling valve 70 having the heads 0' and p and the neck may bemounted in the back cylinder portion P adjacent the ratchet ring Q inposition to be actuated by a stop r, shown in the form of a radial armextending from the ratchet ring Q opposite the head 0 of the valve 7a.

The valve Z: is normally maintained in closed position as by means ofthe spring .9 or other suitable device which is of suflicient strengthto normally resist the thrust of the ratchet ring. A cap t having a ventit covers the portion of the back cylinder portion P forming the valvecasing. .Asshown in Figure 2 the valve head. 72 normally closescommunication between the exhaust passage h and the exhaust port 7, butupon a Slliilcient increase of the resistance to rotation to cause thestop or armr on the ratchet ring to bear against the valve l:withsullicient' force to overcome and compress the spring 8, the valvewill be EIIOVGClfOOPGIl position as indicated. thusrelieving thepressure in the air feed cylinder and re lucing the feed. VVhentherotation again becomes normal theratchet ring will permit the valve 70to close and normal rotation and air feed will be resumed.

automatically controlling the feeding means.

2. In a rock drill of the hammer type, the combination of a cylinder andrecipro-- eating hammer piston, operative devices cooperating with thehammer piston for auto-- matically rotating the dull steel, means for.

feeding the machine forward, and means a0 tuated by the rotatingdevicesresponsively The device operates automatically to control the air to theresistance to rotation for automatically controlling the feeding means.

3. In a rock drill of the hammer type, the combination of a cylinder andreciprocating hammer piston, operative devices cooperating with thehammer piston, and including a rifle bar and ratchet and pawl device forautomatically rotating the drill steel, means'for feeding the machineforward, and means actuated by the ratchet and pawl device responsivelyto the resistance to rotation for automatically controlling the feedingmeans.

4. In a rock drill of the hammer type, the combination of rifle barrotation for the drill steel, means for feeding the machine forward, andmeans controlled by the rifle bar and responsive to the resistance torotation for automatically controlling the feeding means.

In a rock drill of the hammer type combination of means for feeding themachine forward, and means controlled by backward slip of the rotatingdevices for automatically controlling the feeding means.

6. In a rock drill of the hammer type. the combination of rifle barrotation for the drill steel having a ratchet ring adapted to move uponincrease of the resistance to rotation, means for feeding theinachineforward, and a valve opposing the movement of the ratchet ringand connected to automati- -cally control the feeding means inaccordance with the resistance to rotation.

7. In arock drill of the hammer type, the combination of rifle barrotation for the drill steel havinga ratchet ring-adapted to move uponincrease .of the resistance to rotation, means for feeding, the machineforward, a stop on the ratchet ring, and a valve mounted adjacent theratchet ring and actuated by said stopsaid valve controllingthe feedingmeans, whereby the feed is automatically regulated in accordance withthe resistance to rotation, V

In testimony whereof I have signed this specification.

LEWIS C. BAYLES,

